×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

electrolytic plating

electrolytic plating

electrolytic plating

(OP)
I Would like to know if someone have  an experience with  an electrolytic plating type chrome on a piece in Monel.
Is it possible?
It is for a pump shaft, and an  application in sea water . An error was made  during machining, we have 2 solutions:

first : electroplating
second: Reject the shaft.

Thank your for your help.

JL

RE: electrolytic plating

I would not recommend chrome plating as a long-term solution due to galvanic incompatibility in seawater.  Chromium is anodic vs. Monel®, and chrome plating is normally micro-cracked, so eventually the chrome would dissolve.  However, I do not know your design.  Possibly, applying a sealant where the propeller hub fits over the shaft and using sealed, lubricated bearings will suffice if exposed shaft areas do not matter.

For a supporting reference, see MIL-STD-889B, Table II Galvanic Series of Metal in Seawater:  Note the wide separation between Chromium plating and Monel.  Also, see Table 1 Guide to Use of Joined Metals (most recent version is in Notice 3). The ‘I’ in the center of the cell where the chromium row intersects the Monel column indicates galvanic incompatibility in seawater.  Note the ‘C’ in the lower left corner, which indicates compatibility in marine atmospheres (non-immersion).  
Corrosion minimization treatments are given in Appendix A. Resin coating of the chromium plating is one method.  MIL-STD-889B is available at
http://assist1.daps.dla.mil/quicksearch/

Another idea would be to rebuild the surface by alternatingly plating thin layers of Ni and Cu, of about 2:1 thickness ratio, followed by a diffusion anneal at 800 or 900oC in a protective atmosphere. However, the cost and risk of shaft warping are probably enough to justify ordering a new shaft.

Hope this helps,
Ken

RE: electrolytic plating

(OP)
Thank you for help and links.

JLuc

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

eBook - Integrating the Engineering Ecosystem
Aras Innovator provides multiple options for integrating data between systems, depending on the scenario. Utilizing the right approach to meet specific business requirements is vital. These needs range from authoring tools, federating data from various and dissimilar databases, and triggering processes and workflows. Download Now
White Paper - Industry 4.0 and the Future of Engineering Education
With industries becoming more automated, more tech-driven and more complex, engineers need to keep their skills and knowledge up to date in order to stay on top of this wave—and to be prepared for the Industry 4.0 future. The University of Cincinnati offers two online Master of Engineering degree programs designed specifically for practicing engineers. Download Now
eBook - The Design Gridlock Manifesto
In this eBook, you’ll learn 6 ways old CAD technology slows your company down and hear how design teams have put those problems to rest. “The Design Gridlock Manifesto” shares first-hand modern CAD experiences from 15 companies around the world. Download Now
White Paper - Comparing Multi-Patterning at 5nm: SADP, SAQP, and SALELE
Self-aligned multi-patterning techniques such as SADP, SAQP, and SALELE are increasingly popular at advanced nodes, but each process has its pros and cons. IMEC and Mentor, a Siemens business collaborated to identify potentially less-obvious process and design limitations and trade-offs between the three SAMP techniques. Learn more in this paper. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close